Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 146: | \[{21^{146}-1\over20}\] | 2 × 11 × 293 × 439 × 877 × 1607 × 30661 × 8303167 × 9428689079641451<16> × 1427364308750988577<19> × 7464630301668237280651468212188413809960173<43> × 5424905842809814580790135175148153005273370039115139875248165723989059011789226683837426053<91> |